Projection apparatus



Sept. 3, 1935. J. EGGERT El AL PROJECTION APPARATUS Filed Feb. 19, 1934 w. I I

In ven fora:

Patina... 3.193s 2,013,178

UNITED STATES PATENT OFFICE PROJECTION APPARATUS John Eggert, Leipzig-Goblin, and Gerd Heymer, Woli'en Kreis Bitterleld, Germany, assignors to I. G. Farbenindustrle Aktiengesellschai't, Franktort-on-the-Main, Germany Application February 19, 1934, Serial No. 712,078 In Germany February 22, 1933 2 Claims. (Cl. 88-164) Our present invention relates to the projection by the lenticular elements on the margins of the of lenticular film. film are displaced towards the edges of the film. One of its objects is an apparatus for project- This displacement depends on the distance of the ing lenticular film. Further objects will be seen virtual image of the filter from the film in taking. from the detailed specification following here- A-good reproduction of the colors is only obtained 5 after. if in projection the multi-color filter is arranged It has already been proposed to use the multiat the same distance from the film as the virtual color filter necessary for projecting lenticular image oi the filter was arranged from the original films in natural colors a lamp mirror which has in taking. As in the present case the multi-color ,0 been subdivided into zones of different color in filter is replaced by colored projection lamps, the accordance with the otherwise used multi-color latter must be arranged in the optical centers of filter. Though with this arrangement a good the areas of. the virtual image of the taking filter. yield of the light employed is obtained, the colors In projection the gas discharge lamps blue, green of the reproduced'picture are considerably turned and red must therefore be arranged in the optical 5 into white, if the picture is produced with suilicenters of the filter areas in taking it a multicient brightness. Furthermore, it is not possible color filter with these colors has been used. In to vary separately the intensity 0! the difierent-ly Fig. 1 there are arranged the lamps L1, L2 and L: colored portions of. the projection light, as it is in the optical centers 1), a and r 01' the blue, the often desirable. These drawbacks are overcome green and the red filter strip of the taking filter. o by the present invention. Fig. 2 shows repeatedly bent discharge tubes According to this invention the source of light arranged in accordance with the principles deconsists of a series of gas discharge lamps having scribed with reference to Fig. 1. In this case the different colors. These lamps are so arranged corresponding filter area is illuminated to a greatthat, when viewed from the side of the film, they er extent. lie in the optical center occupied during the tak- Fig. 3 shows a simple device by which the diil'er- :5 ing and the preparation of the print by the virtual ently colored gas discharge lamps can be laterally filter image. displaced. This possibility is necessary ii the same The source 01 light normally used is composed device shall be used for the projection of films of three gas discharge lamps radiating light in which have been taken with different filters.

is, however,'also possible to use any number of 1. In an apparatus for projecting lenticular lamps radiating colored light according to refilm in combination, a lenticular film, and at a q ir men The di r n lamps a p f r ly distance from the film in the plane which is usualso mounted that they can be displaced against one ly occupied by the multi-color filter gas dischargii another and that the system of lamps, as a whole ing lamps assuming on electrical excitation the re- 85 may be adapted to difierent sizes of the taking quired colors for reproducing the original on said filter. film in natural colors and arranged at places cor- The invention will now be described with refresponding with the optical centers of the filter erence to the accompanying drawing in which strips of the otherwise used multi-color filter.

.0 Fig. 1 shows an arrangement for projection ac- 2. In an apparatus for projecting lenticular -40 cording to this invention, film in combination, a lenticular film, and at a dis- Fig. 2 shows gas discharge lamps for projecttance from the film in the plane which is usua y ing according to the invention, and occupied by the multi-color filter gas discharging Fig. 3 shows a device for displacing the gas dislamps 38811 8 n e ec cal excitation the e- .5 charge lamps. quired colors for reproducing the original on said Referring to Fig. l, A designates the lenticular film in natural colors and arranged at places corfilm, B indicates the position of the virtual image responding with the optical centers oi the filter of the multicolor filter with which the lenticular strips of the otherwise used multi-color filter, and film has been taken. This virtual image is promeans for laterally displacing said gas dischargjected in the photographic layer D of the film ing tubes. so by the lenticular elements in such a manner that JOHN EGGERT. images of the virtual image of the filter projected GERD HEYMER.

the fundamental colors red, green and blue. It What we claim is: 

